Fish Surveys

Published

April 24, 2024

Metadata

Figure 1: Location of fish surveys

Table 1: Summary of work by island and exposure

Number of fish surveys per location, habitat, and exposure
	Exposure	Strata	# Sites	# Transects	# Reels	Surveyed distance (m)
Fanna
Forereef	Leeward	2	1	2	6	150
Forereef	Windward	2	5	10	30	750
Total	—	—	6	12	36	900
Helen
Backreef	Lagoon	1	1	2	6	150
Patchreef	Lagoon	2	3	6	18	450
Forereef	Leeward	2	6	12	36	900
Forereef	Windward	2	5	10	30	750
Total	—	—	15	30	90	2250
Merir
Forereef	Leeward	2	3	6	18	450
Forereef	Windward	2	4	8	24	600
Total	—	—	7	14	42	1050
Pulo Anna
Forereef	Leeward	2	2	4	12	300
Forereef	Windward	2	2	4	12	300
Total	—	—	4	8	24	600
Sonsorol
Forereef	Leeward	2	4	8	24	600
Forereef	Windward	2	3	6	18	450
Total	—	—	7	14	42	1050
Tobi
Forereef	Leeward	2	5	10	30	750
Forereef	Windward	2	1	2	6	150
Total	—	—	6	12	36	900
Grand total	—	—	45	90	270	6750

Pointblank Validation
Validate taxa list tibble fish_lutWARN 1 STOP — NOTIFY —
		STEP	COLUMNS	VALUES	TBL	EVAL	UNITS	PASS	FAIL	W	S	N	EXT
	1	`rows_complete()`	`▮taxon_code,` `▮taxon_valid_name,` `▮max_length_tl,` `▮a,` `▮b,` `▮common_family,` `▮consumer,` `▮trophic,` `▮trophic_detailed`	—		✓	`413`	`412` `0.99`	`1` `0.01`	●	—	—
	2	`rows_distinct()`	`▮taxon_code`	—		✓	`413`	`413` `1`	`0` `0`	○	—	—	—
2024-04-19 18:30:22 -05 < 1 s 2024-04-19 18:30:22 -05

Pointblank Validation
Validate observations tibble mutate(fish_obs, diff = (avg_tl_cm - max_length_tl)/max_length_tl)WARN 1 STOP — NOTIFY —
		STEP	COLUMNS	VALUES	TBL	EVAL	UNITS	PASS	FAIL	W	S	N	EXT
	1	`col_vals_not_null()`	`▮taxon_code`	—		✓	`11779`	`11779` `1`	`0` `0`	○	—	—	—
	2	`col_vals_not_null()`	`▮n_ind`	—		✓	`11779`	`11779` `1`	`0` `0`	○	—	—	—
	3	`col_vals_not_null()`	`▮min_tl_cm`	—		✓	`11779`	`11779` `1`	`0` `0`	○	—	—	—
	4	`col_vals_not_null()`	`▮max_tl_cm`	—		✓	`11779`	`11779` `1`	`0` `0`	○	—	—	—
	5	`col_vals_gte()`	`▮max_tl_cm`	`▮min_tl_cm`		✓	`11779`	`11779` `1`	`0` `0`	○	—	—	—
	6	`col_vals_lte()`	`▮diff`	`0.1`		✓	`11779`	`11579` `0.98302`	`200` `0.01698`	●	—	—
2024-04-19 18:30:28 -05 < 1 s 2024-04-19 18:30:28 -05

Table 2: Summary of results by island and depth strata.

Average species richness, abundance, and biomass by location
	Sites	# Transects	# Reels	# Taxa	Abundance (ind/m2)	Biomass (g/m2)
Fanna
Deep	6	6	18	77.50	13.76	751.79
Shallow	6	6	18	60.83	14.36	328.67
Overall	—	12	36	69	14	540
Helen
Deep	14	15	45	67.53	6.82	695.71
Shallow	14	15	45	74.87	9.74	644.16
Overall	—	30	90	71	8	670
Merir
Deep	7	7	21	67.57	6.33	875.60
Shallow	7	7	21	73.29	5.68	696.25
Overall	—	14	42	70	6	786
Pulo Anna
Deep	4	4	12	61.25	17.72	1431.38
Shallow	4	4	12	67.50	10.43	756.39
Overall	—	8	24	64	14	1094
Sonsorol
Deep	7	7	21	72.43	17.38	552.97
Shallow	7	7	21	64.00	17.17	439.25
Overall	—	14	42	68	17	496
Tobi
Deep	6	6	18	69.50	7.87	875.77
Shallow	6	6	18	73.00	13.96	671.98
Overall	—	12	36	71	11	774

Figure 2: Number of species by order and family

Table 3: Results of Adonis model for univariate analysis of fish species richness

Results of Adonis model for univariate analysis of fish species richness
	df	SumOfSqs	R2	statistic	p.value
depth_strata	1	19.699	0.002	0.155	0.693
location	5	690.066	0.060	1.086	0.383
exposure	1	859.704	0.075	6.763	0.010
habitat	1	15.851	0.001	0.125	0.735
diver	1	16.078	0.001	0.126	0.715
Residual	79	10042.063	0.876	NA	NA
Total	89	11463.122	1.000	NA	NA

Figure 5: Fish abundance by island

Table 4: Results of Adonis model for univariate analysis of fish abundance

Results of Adonis model for univariate analysis of fish abundance
	df	SumOfSqs	R2	statistic	p.value
depth_strata	1	29.142	0.006	0.764	0.385
location	5	1239.959	0.235	6.498	0.001
exposure	1	227.512	0.043	5.961	0.017
habitat	1	2.027	0.000	0.053	0.810
diver	1	698.274	0.132	18.296	0.001
Residual	79	3015.149	0.571	NA	NA
Total	89	5280.030	1.000	NA	NA

Table 5: Results of Adonis model for univariate analysis of fish biomass

Results of Adonis model for univariate analysis of fish biomass
	df	SumOfSqs	R2	statistic	p.value
diver	1	262789.72	0.014	1.877	0.188
depth_strata	1	949917.15	0.051	6.786	0.010
habitat	1	16167.88	0.001	0.115	0.716
exposure	1	1620763.36	0.086	11.578	0.001
location	5	3180210.90	0.170	4.544	0.001
Residual	79	11058559.51	0.590	NA	NA
Total	89	18743039.71	1.000	NA	NA

Table 6: Summary of results by island and exposure

Average species richness, abundance, and biomass by location and exposure
	Sites	# Transects	# Reels	# Taxa	Abundance (ind/m2)	Biomass (g/m2)
Fanna
Leeward	1	2	6	69.50	10.40	812.13
Windward	5	10	30	69.10	14.79	485.85
Helen
Lagoon	4	8	24	67.50	8.04	190.96
Leeward	6	12	36	66.42	6.02	543.22
Windward	5	10	30	79.90	11.18	1205.17
Merir
Leeward	3	6	18	68.17	5.40	867.76
Windward	4	8	24	72.12	6.46	724.54
Pulo Anna
Leeward	2	4	12	62.00	13.51	667.85
Windward	2	4	12	66.75	14.64	1519.92
Sonsorol
Leeward	4	8	24	65.38	13.97	399.11
Windward	3	6	18	72.00	21.68	625.44
Tobi
Leeward	5	10	30	70.80	11.36	744.70
Windward	1	2	6	73.50	8.67	919.77

Figure 11: Biomass by family

Figure 12: Biomass by family and depth strata

Figure 13: Biomass by trophic group

Figure 14: Frequency, abundance, and biomass by species

Table 7: Fish assemblages Adonis model

Results of community composition Adonis model
term	df	SumOfSqs	R2	statistic	p.value
location	5	5.168	0.170	3.820	0.001
exposure	1	0.358	0.012	1.324	0.119
habitat	1	0.404	0.013	1.493	0.048
depth_strata	1	0.810	0.027	2.993	0.001
Residual	80	21.648	0.713	NA	NA
Total	89	30.376	1.000	NA	NA

Table 8: Results of ANOVA on the ordination model

Significance of each term in the ordination model
term	df	SumOfSqs	statistic	p.value
location	5	6.231	2.860	0.001
exposure	2	2.446	2.806	0.001
depth_strata	1	0.968	2.222	0.001
habitat	1	0.569	1.306	0.064
Residual	80	34.865	NA	NA